Rough running

[bjbrownie]

Just started up my DMC after a month in the garage and although it fired up immediately, it ran very rough after the engine revs shot up to nearly 4k, then settled down to a lumpy tickover (like on 4 cylinders)and then idled at 800 rpm gradually falling off till it stalled. It ran perfectly at the beginning of January, 1/4 tank of fuel and run till it was hot, so this is unusual. Restarts easily but very lumpy idle-accelerator has little effect, pushing the pressure flap on the injector body makes it pick up but still rough. Ignition in good order, mixture etc fine when last adjusted-any ideas?

[Chris Williams]

Fresh fuel and a good drive cures a lot of ills!!!!

Chris

[stunned_monkey]

Check the vacuum hoses are all connected as per the diagram under your engine cover.

[bjbrownie]

Thanks for the pointers, it was an air leak in the flexible connection joining the intake throttles to the injector air assembly-there was a split in the lower part of the convoluted hose, I removed it back in summer and it appeared fine, maybe age and -14 temperatures must have seen it off. New part on its way asap 8)

[Guinney1971]

glad to hear this was an easy fix

We're gonna make a start on sorting Flopsy out soon, we *think* its got a
dodgy injector (plus loads of other faults).

Just need to finish the engine transplant in one of our Cavaliers first, then we
can turn out attention to the Flopmeister

[Rich Hanlon]

Air leaks can be spectacularly bad news for engine running - just removing the rubber blank that covers the mixture adjustment screw, changes mine from running perfectly to a bag of rats, in one easy step.

Adjusting the three brass screws on the inlet plenum pipes can make a lot of diffference too...

R

[bjbrownie]

I wound all 3 brass screws in (as I read somewhere), tickover was a lt smoother, winding them out to Volvo manual spec didnt improve anything much but raised the revs a little and made the engine idle a bit lumpy-best leave them screwed in and recheck the emissions 8)